This mat has little spikes on the under side which keep it from sliding around when I move my chair. Unfortunately when I sit in one place for a while the chair creates dents in the mat; then when I try to move the chair rolls back into the dents! I'm not sure what I'll do about that.
The mat arrived without packaging and was filthy - it had to be cleaned before putting down on the carpet in my office. Even though it is "heavy duty" it still dimples making chair movement a little difficult. Bottom line - it's just OK.